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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-10-13 18:04:09 +0200 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2021-10-16 22:41:25 -0700 |
| commit | 2c59a32d12201b4aeaef5c0cc04698670e164dc3 (patch) | |
| tree | 3a8c28b92063a792eda33a41df3df2c73ee21330 /drivers | |
| parent | b1986c8e31a3e5f119a52aab50234fc65cf01f30 (diff) | |
| download | linux-rpi-2c59a32d12201b4aeaef5c0cc04698670e164dc3.tar.gz linux-rpi-2c59a32d12201b4aeaef5c0cc04698670e164dc3.tar.bz2 linux-rpi-2c59a32d12201b4aeaef5c0cc04698670e164dc3.zip | |
hwmon: (acpi_power_meter) Use acpi_bus_get_acpi_device()
In read_domain_devices(), acpi_bus_get_device() is called to obtain
the ACPI device object attached to the given ACPI handle and
subsequently that object is passed to get_device() for reference
counting, but there is a window between the acpi_bus_get_device()
and get_device() calls in which the ACPI device object in question
may go away.
To address this issue, make read_domain_devices() use
acpi_bus_get_acpi_device() to reference count and return the given
ACPI device object in one go and export that function to modules.
While at it, also make read_domain_devices() and
remove_domain_devices() use acpi_dev_put() instead of calling
put_device() directly on the ACPI device objects returned by
acpi_bus_get_acpi_device().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/11871063.O9o76ZdvQC@kreacher
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/scan.c | 1 | ||||
| -rw-r--r-- | drivers/hwmon/acpi_power_meter.c | 13 |
2 files changed, 6 insertions, 8 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 5b54c80b9d32..f456ba7c1060 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -608,6 +608,7 @@ struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle) { return handle_to_device(handle, get_acpi_device); } +EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device); static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) { diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c index 014505b1faf7..c405a5869581 100644 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -535,7 +535,7 @@ static void remove_domain_devices(struct acpi_power_meter_resource *resource) sysfs_remove_link(resource->holders_dir, kobject_name(&obj->dev.kobj)); - put_device(&obj->dev); + acpi_dev_put(obj); } kfree(resource->domain_devices); @@ -597,18 +597,15 @@ static int read_domain_devices(struct acpi_power_meter_resource *resource) continue; /* Create a symlink to domain objects */ - resource->domain_devices[i] = NULL; - if (acpi_bus_get_device(element->reference.handle, - &resource->domain_devices[i])) + obj = acpi_bus_get_acpi_device(element->reference.handle); + resource->domain_devices[i] = obj; + if (!obj) continue; - obj = resource->domain_devices[i]; - get_device(&obj->dev); - res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj, kobject_name(&obj->dev.kobj)); if (res) { - put_device(&obj->dev); + acpi_dev_put(obj); resource->domain_devices[i] = NULL; } } |